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离子特异性效应在固/液界面反应中普遍存在.土壤溶液中包含众多阴离子和阳离子,由于土壤带净负电荷,其中阴离子对土壤颗粒凝聚的影响被认为很微弱甚至在很多情况下被忽略.以蒙脱石胶体悬液为研究对象,基于动态光散射技术测定了几种不同的一价阴离子(H_2PO_4~-,Cl~-和NO_3~-)对蒙脱石胶体凝聚的影响.研究结果表明,H_2PO_4~-,Cl~-和NO_3~-体系下的凝聚速率显著不同,临界聚沉浓度分别为79.29,13.91,17.07mmol/L,活化能表征的离子特异性效应序列由大到小为H_2PO_4~-,NO_3~-,Cl~-,这意味着阴离子特异性效应会显著影响带负电荷胶体的凝聚.上述差异主要是由几种阴离子核外电子云结构的差异带来的极化效应不同引发的.
The ion-specific effect is ubiquitous in the solid / liquid interface reaction, and the soil solution contains many anions and cations. The effect of anions on soil particle agglomeration due to the net negative charge of the soil is considered weak or even neglected in many cases. The effects of several monovalent anions (H_2PO_4 ~ -, Cl ~ - and NO_3 ~ -) on the aggregation of montmorillonite colloids were studied by using the dynamic light scattering technique, taking the montmorillonite colloidal suspension as the research object. , H_2PO_4 ~ -, Cl ~ - and NO_3 ~ -, the critical aggregation concentrations were 79.29, 13.91 and 17.07 mmol / L respectively. The ion-specific effect sequence characterized by activation energy was desorbed as H_2PO_4 ~ -, NO_3 ~ -, Cl ~ -, which means that the anion-specific effect will significantly affect the aggregation of negatively charged colloids.The above differences are mainly caused by the difference in polarization effects Caused.